Threading machine die head



M. w. LAMPRE CHT 2,292,788. THREADING MACHINE DIE mm) I Filed July 22, 1940 2 Sheets-Sheet 2 FIG-4 INVENTOR MERLE W. LAMPRECHT ATTORN EYS Patented Aug. 11, 1942 THREADING MACHINE DIE HEAD Merle W. Lamprecht, Rocky River, Ohio, assignor to The Hill Acme Company, Cleveland, Ohio, a corporation of Ohio Application July 22, 1940, Serial No. 346,698

8 Claims.

This invention relates to improvements in a die head for a thread cutting machine.

One of the objects of the present invention is to provide a die head with tangent die holders adapted to oscillate in a plane at right angles to the axis of the head, together with a member movable longitudinally of the head both for the purpose of setting the opening between the dies for the threading of a given diameter of stock and also for the opening and closing of the die holders at the beginning and ending of the threading operation.

Another object of the present invention is to provide a very simple structure adapted to control the oscillating die holders while at the same time holding them very rigidly so that very accurate threads may be cut.

Another object of the present invention is to provide tangential die holders with means for adjusting their position while the die head is rotating.

Another object of the invention is to provide a very novel arrangement for controlling the'position of the tangential die holders including a removable block adapted to be placed in several positions and having an operative connection spaced at difierent distances from various edges of the block so that the positioning of the die holders for various sizes of work is controlled by the position of this block.

My invention also includes the various structural forms and arrangements of parts hereinafter disclosed to carryout the purposes mentioned and the essential features thereof will be summarized in the claims.

In the drawings, Fig. 1 is a side elevation of my improved die head, portions thereof being broken away to show .the parts in central longitudinal section so that the structure may be more clearly comprehended; Fig. 2 is a frontjeleupon which is secured by threading or the like a rotatable barrel l2. The barrel has a central opening I3 lined with a hardened steel bushing M for the reception of stock to'be threaded. The barrel I2 is generally cylindrical and is provided at its forward end with a plurality of radially extending pockets I5, in the present instance four of such pockets being provided. These pockets have a hardened steel lining I6 and are closed at their forward end by a hardened steel face plate I! which is secured by screws to the body of the barrel. Radially slidable in each pocket is a die slide [8. Each die slide overhangs the face plate Il as indicated at lBa on Fig. 1 and is there provided with a forwardly extending round pin [9 which provides a connection with the die holders as will presently appear.

Each die slide I8 is connected with a die holder 20 which is of the general shape shown on Figs. 3, 4 and 5. Each holder is provided with an ear 20a which is bored to engage a pivot pin 2| which is held in the barrel by the face plate H. A cap member 22 is secured by a screw 23 to the pin 2! so as to hold the ear 20a on its associated pivot pin with practically no play. Each holder has a flat face 202) to which is secured a die or chaser 24 in a position tangential to the stock to be threaded. An inset die securing cap 25 secures the die to the holder. Each holder is provided with a slot 25 which extends substantially at right angles to the fiat face 20b and the die 24. In each slot 26 is a square block 21 having a round hole 28 adapted to fit upon the pin IQ of its associated slide.

Certain of the advantages of my invention are realized whatever the shape of the block 21 and the location of the hole 28 therein. However, I provide a novel means by which the. block 21 may be used in different positions to adjust the die head for working upon various sizes of stock. To this end the block 21 is made square and the hole 28 is eccentrically positioned at different dis- 'tances from at least two, and preferably from each of the four side edges of the block. Referring to Fig. 5, it will be noted that the spaces a, b, c and d progressively increase so that the die holders assume various positions depending upon the position of the block 21 in the slot 26.

Referring to Fig. 3, it will be noted that the radial pockets l5 in the barrel and the slots 26 in the holders 20 provide movement in planes lying at an angle to each other so that as the die slides I8 move radially outwardly, the holders 20 V are oscillated in a direction to open the dies.

The means for controlling the radial position of the die slides l8 comprises a die ring 29 embracing the barrel l2 and slidable thereon where their surfaces mutually engage at 30. The radially outermost faces of the die slides are inclined toward the axis of the head from the front to the rear of each die slide as indicated at lb. The die ring 29 is provided with pockets 3| for receiving the radially outermost portions of the slides l8. One of these pockets is clearly indicated in Fig. 3. Referring to Fig. 1, each of these pockets has an inclined face 32 complementary to the surface IBb of its associated slide. Each slide is generally T-shape as best seen in Fig. 3 and the pocket 3| is of a complementary shape so that the die slides are definitely held in radial positions depending upon the movement of the die ring 29 axially of the barrel. Preferably the T-shape portion of each pocket 3| is provided with a hardened steel lining.

The position of the die ring 29 relative to the barrel :2 is controlled by a yoke 33 which engages in an annular groove 34 in ring 29. The position of the yoke 33 is controlled both above and below the die head. The connection below the die head is by means of a pin 35 in a slot 36 of an arm 3'! which is pivotally mounted on the main frame or housing at 38. The arm 31 is normally held in the position of Fig. 1 by means of latch 39. The arm 31 is integral with shaft 59 which also has rigidly mounted upon it a detent 41a which is a portion of arm 4:. This detent engages at 62 behind the shoulder of the latch 39 and holds arms 37 and 4| against counterclockwise movement. When the work is finished a gage rod engages the inclined face 39a of the latch, raising it out of engagement with the detent thus permitting arms 37 and 4| to move in counterclockwise direction as viewed in Fig. l impelled by springs 43 and 44, respectively, which are engaged between collars on rods 45 and 45, respectively, and fixed portions of the frame. It will thus be obvious that upon completion of a threading operation and assuming that the up er end of the yoke 33 is held in position, then the movement of arm 31 in a counterclockwise direction upon release of latch 39 will carry oke 33 and die ring 29 toward the right as viewed in Fig. 1 so as to permit the slides Hi to move radially outwardly and thus open the dies.

Means is provided for adjusting the opening between the dies While the head is rotating. This means is provided at the upper connection of yoke 33. Pin 47 connects the yoke with a block 43 which has threaded engagement with a shaft 49 which is rotatable by means of hand wheel 50. A scale at Elf and a Vernier at 52 permits a very fine adjustment at this point. This adjustment is useful regardless of the shape of the block 21 and the location of the hole 28 as previously described, but in the machine as here disclosed the general setting of the dies for the size of work is determined by the positioning of the block 21 as best viewed in Fig. 5, and the fine adjustment by means of hand wheel 50 is made while the machine is running. Obviously movement of the block 48 along the shaft 49 moves the yoke 33 and the die ring 29 so that the surfaces 32 of the die ring control the radial position of the slides 53.

Means is also provided for opening the dies by hand. This comprises a handle 53 rigid with shaft 40.

The cap members 22 which serve to hold each die holder in position on the head are also utilized for another purpose. Referring to Fig. 3 there will be noted near the cutting edge 54 of the die 2d a shoulder 55 on the die holder 23 which provides a face parallel to the plane of oscillation of the die holder. The cap member 22 overlies the shoulder 55 at the point 56 and is provided with a coacting parallel surface so that the cap member 22 serves to hold the shoulder 55 and therefore the nose of the cutting die firmly in position against the forward face of the head so as to provide great rigidity for the thread cutting tool. At the same time the engaging parallel surfaces at 56 permit the oscillation' of the holder 20 as indicated in dot-dash lines in the lower portion of Fig. 3 during the opening and closing of the dies.

What I claim is:

1. A die head comprising a rotatable barrel, die slides mounted in said barrel for radial movement, tangential die holders having a fixed pivotal mounting on the front face of said barrel,

there being an operative connection between each of said slides and its associated holder for causing oscillation of the holder by radial movement of the slide, said connection comprising an abutment movable by a slide and engaging its associated holder at a, point spaced from its .pivotal mounting, all of said slides having similarly formed longitudinally extending inclined faces, and a die ring having inclined faces engaging and coacting with said inclined faces of said slides and adapted to control the radial position of said slides by longitudinal movement of said ring.

2. A die head comprising a rotatable barrel having a front face normal to the axis thereof, die slides mounted in said barrel for radial movement, tangential die holders pivotally mounted on the front face of said barrel, there being a rectilineal slot in each holder extending at an angle to the radial path of its associated slide, a block slidably positioned in each slot, there being a pin and hole connection between each block and its associated slide, each of said slides having a similarly formed inclined radially outermost face, and a die ring embracing said barrel and having inclined faces engaging and coacting with said inclined faces of said slides and adapted to control the radial position of said slides by longitudinal movement of said ring.

3. A die head comprising a rotatable barrel having a front face normal to the axis thereof, die slides mounted in said barrel for radial move ment, means controlling the radial movement of said slides, tangential die holders pivotally mounted on the front face of said barrel, there being a rectilineal slot in each holder extending at an angle to the radial path of its associated slide, a square block slidably positioned in each slot, there being a pin and hole connection between each block and its associated slide, and said pin and hole connection being located different distances from at least two sides of said block, whereby different positions of said blocks in said slots will give different positions of said holders with the same radial position of said slides.

4. A die head as in claim 3 wherein said pin and slot connection is located different distances from each of the four sides of said block, whereby four different positions are provided.

5. A die head comprising a rotatable barrel, a plurality of die holders mounted on said barrel for movement toward and away from each other, means controlling the position of said die holders including a guideway in said holder and a square block slidable in said guideway and a part coacting with said block, and a pin and hole connection between said block and part, said pin and hole connection being located different distances from at least two sides of said block, whereby said square block may occupy different positions in said guideway to vary the relation between said pin and hole connection and said holder.

6. A die head comprising a plurality of pivotally mounted die holders, means securing one of said holders to its pivotal mounting, and said means engaging another of said holders at a point remote from its pivotal mounting to steady said other holder.

7. A die head comprising a plurality of tangential die holders pivotally mounted on said head, a die rigidly mounted on each holder and having a cutting edge, a separate securing member for each holder associated with the pivotal mounting thereof to secure the holder to the head, and each securing member engaging another holder near its cutting edge and holding said other holder substantially rigidly during a cutting operation.

8. A die head comprising a plurality of tangential die holders pivotally mounted on said head in a common plane, a die rigidly mounted on each holder and having a cutting edge, an abutment on each holder near its cutting edge, each abutment lying ina plane parallel to the plane of oscillation of said holders, a separate securing member for securing each holder to its pivotal mounting, and the securing member for one holder having a face parallel to said plane of oscillation and slidably engaging said abutment of another holder, whereby to hold said other holder against movement out of said plane while permitting oscillation of said holder in said plane.

MERLE W. LAMPRECHT. 

